So-called electronic books are known in the art and are increasingly becoming a part of ordinary life. In an, electronic book, documents are presented to a reader using a computer-based display device. Examples of such devices are the “ROCKET EBOOK” device by NuvoMedia, Inc. and the “SOFTBOOK READER” device by Softbook Press, Inc. One aspect of printed books that may be desirable to replicate in electronic books is the use of consistently reproducible pages and page numbers. However, in the context of electronic documents, certain challenges exist in providing reproducible pages and page numbers to users of an electronic book. A particular problem is how to quickly provide, accurate, reproducible pages and page numbers after a user has opened an electronic book to an essentially unknown location in the book. This problem is reflected in the fact that the “ROCKET EBOOK” device currently does not support the use of page numbers.
The technique of background pagination is generally known in the art of electronic documents. Using this technique, a user may choose to view a selected portion of a document in paginated or print-preview form. While the user is viewing a selected portion of the document, the computer accesses the file storing the document, locates the beginning of the document and recalculates page boundaries going forward until it reaches the selected portion thereby determining a stable page. By keeping a running page count as new page boundaries are recalculated, a page number for the selected portion may also be determined. While this method works, it is processor-intensive and, for any document of significant length (such as a novel) is often likely to take a significant amount of time to complete.
Another solution is to include page information in the computer-readable file storing the document. Thus, along with the text and image data forming the content of the document, one would embed information indicative of page numbers at appropriate locations. However, the page number data embedded in this manner would no longer be accurate in the event that the document is re-formatted, for example, in response to a change in font size of the text. Further still, this implementation would make the format inflexible with respect to display of the document on different sized devices.
Thus, it would be advantageous to provide a technique for efficient determination of reproducible pages of electronic documents, particularly in response to a user opening a document to an otherwise unknown point in the document.